THURSDAY, Feb. 23 (HealthDay News) -- That constant sneezing you thought was a winter cold might just be the beginning of your spring allergies instead.

Many areas of the United States have had warmer-than-average winter weather, which is causing trees to start pollinating earlier in some places, according to Dr. Stanley Fineman, president of the American College of Allergy, Asthma & Immunology (ACAAI).

"What we're finding is the warmer weather is bringing earlier pollination of the trees. Here in Atlanta, we already have unusually high pollen counts for this time of the year, and people are starting to have symptoms already," he said.

Asked if the early start would also mean an early end to allergy season, Fineman said he didn't think so. "I think the spring allergy season will probably be longer. In the past few years, it's seemed to start earlier, but then seems to last as long as usual," he noted.

Another expert agreed. "If you have a warmer winter, it's likely that you'll have a longer and worse pollen season," said Dr. Punita Ponda, an attending physician in the pediatric allergy and immunology division at Cohen Children's Medical Center of New York in New Hyde Park.

But, Ponda pointed out that it's not always a warmer winter that brings more pollen. Last year, it was a particularly wet winter in the New York area, with much greater than normal snowfall.

"Last year was a cold, cold winter with a lot of snow, and it was followed by a pretty impressive pollen season," she said, adding that the longer pollen seasons may actually have more to do with global warming than the year-to-year variations in weather. "So, it may be that next year we'll have a long spring pollen season, whether or not it was a warm winter," she said.

So, how can you tell if your runny nose is caused by a cold or allergies? The biggest clue is time, say the experts. If you have what you think is a cold that lasts longer a week, it may be allergies, according to the ACAAI. Also, allergies don't cause fevers and body aches, whereas a cold or flu can. If the discharge from your nose is clear, it's likely that an allergy is to blame from your misery, according to the ACAAI.

Both Fineman and Ponda said it's important to see an allergist to help identify your triggers through allergy testing. Once you know exactly what makes your allergies flare up, you can take steps to prevent them.

If tree pollen is an issue, Ponda says that she advises her patients -- or their parents -- to follow pollen counts in their area, and if the levels are moderate or high to start taking preventive measures, such as keeping the windows closed. She said it's especially important to take steps to avoid pollen between the hours of 5 a.m. and 10 a.m. when pollen counts are often at their highest.

Other things you can do are to stay inside during high pollen hours whenever possible, and if you have to go out, to use the recirculated air setting for your car's vents. When pollen levels are elevated, it's also a good idea to shower as soon as you come home or at least before bed to avoid spreading pollen in your home and bedroom.

In addition to these self-care steps, Fineman said that there are preventive medications that can often help keep allergies at bay. The first line in treatment is generally over-the-counter antihistamines, such as Allegra or Zyrtec or generic equivalents. For more severe allergies, he said that doctors will often prescribe nasal steroids or antihistamines.

And, for those with really intolerable allergies, Fineman said to consider allergy shots. "Allergy immunotherapy is a long-term treatment that develops a sustained tolerance. It's a more life-changing way of dealing with allergies," he said.